1944664491 has 32 divisors (see below), whose sum is σ = 3252584448. Its totient is φ = 1003998240.

The previous prime is 1944664487. The next prime is 1944664577.

1944664491 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1944664491 - 2² = 1944664487 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1944664491.

It is not an unprimeable number, because it can be changed into a prime (1944664471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11830 + ... + 63476.

It is an arithmetic number, because the mean of its divisors is an integer number (101643264).

Almost surely, 2^1944664491 is an apocalyptic number.

1944664491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1944664491 is a deficient number, since it is larger than the sum of its proper divisors (1307919957).

1944664491 is a wasteful number, since it uses less digits than its factorization.

1944664491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51831.

The product of its digits is 746496, while the sum is 48.

The square root of 1944664491 is about 44098.3502072356. The cubic root of 1944664491 is about 1248.1924789673.

It can be divided in two parts, 1944 and 664491, that added together give a triangular number (666435 = T₁₁₅₄).

The spelling of 1944664491 in words is "one billion, nine hundred forty-four million, six hundred sixty-four thousand, four hundred ninety-one".